atom/static/editor.css

.editor {
  font: 18px Inconsolata, Monaco, Courier !important;
  position: relative;
  width: 100%;
  height: 100%;
  background: #333;
  color: white;
}

.editor pre {
  margin: 0;
}

.editor .cursor {
  background: #9dff9d;
  opacity: .3;
}